Oscillations of hyper- and hypo-response to the potent cytokine IFN-I in individuals with Down syndrome predispose to both lower incidence of viral disease and increased infection-related morbidity and mortality. Credit: Immunity/Malle et al.
People with Down syndrome have less-frequent viral infections. However, when present, these infections lead to more severe disease. New research findings show that this is caused by increased expression of an antiviral cytokine type I interferon , which is partially coded for by chromosome 21. Elevated IFN-I levels lead to hyperactivity of the immune response initially, but the body overcorrects for this to reduce inflammation, leading to increased vulnerability later in the viral attack.
Recently, it has become clear that atypical antiviral responses are another important feature of Down syndrome. Increased rates of hospitalization of people with Down syndrome have been documented for influenza A virus, respiratory syncytial virus, and severe acute respiratory syndrome due to coronavirus infections.